Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F)
as follows:

°F = (1.8 x °C) + 32.

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C)
as follows:

°C = (°F - 32) / 1.8.

Elevation, as used in this report, refers to distance above or below sea level.

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsium
(µS/cm at 25°C).

Concentrations of chemical constituents in water are given either in milligrams per
liter (mg/L), micrograms per liter (µg/L), or picocuries per liter (pCi/L).

Water Year: A water year is a 12-month period, from October 1 through September 30,
designated by the calendar year in which it ends. Years are water years in the report unless
otherwise stated.

Sea level: In this report, "sea level" refers to the National Geodetic Vertical Datum
of 1929 (NGVD of 1929)--a geodetic datum derived from a general adjustment of the first-order
level nets of the United States and Canada, formerly called Sea Level Datum of 1929.

Concentrations, Loads, and Yields of Selected Water-Quality Constituents During Low Flow
and Storm Runoff From Three Watersheds at Fort Leavenworth, Kansas, May 1994 Through September
1996

A study of the effects of storm runoff from urban areas on water quality at Fort Leavenworth,
Kansas, was conducted from May 1994 through September 1996. The purpose of this report is to
present information to assess the current (1994-96) conditions and possible methods for
anticipating future water-quality effects from storm runoff and changes in land use. Three
sampling sites were established to monitor streamflow and water quality from three watersheds
draining the study area. Streamflow was monitored continuously, and water-quality samples were
collected during low-flow (12 samples) and storm-runoff (21 samples) conditions to determine
mean annual constituent loads.

Constituent concentrations for the most part were smallest during low flow with the exception
of major ions, dissolved solids, and some nutrients. Concentrations of suspended solids and
total recoverable metals at all three sites were much larger in storm-runoff samples than in
low-flow samples--typically an order of magnitude larger than low-flow concentrations. Mean
low-flow nutrient concentrations were either larger than or smaller than storm-runoff
concentrations depending on the watershed.

Total chloroform and total tetrachloroethylene were the only two volatile organic compounds
detected, and acid-base/neutral organic compounds were not detected in any of the samples
collected. Eight pesticides were detected in low-flow samples, and 15 pesticides were detected
in storm-runoff samples. The only mean concentrations of the selected constituents in this
study that exceeded either the U.S. Environmental Protection Agency's Maximum Contaminant
Level or the Secondary Maximum Contaminant Level were dissolved solids and total recoverable
iron and manganese.

Mean annual loads for 10 selected constituents were estimated for each watershed. Overall,
storm runoff contributed more than one-half of the total mean annual loads for 8 of the 10
selected constituents. In fact, more than 70 percent of the mean annual loads for suspended
solids and total recoverable copper, lead, and zinc were contributed by storm runoff. More
than one-half the mean annual load was contributed during low flow for dissolved solids at all
watersheds.

Mean annual yields (mass per unit area) of selected constituents from each watershed indicated
few differences between watersheds. The lack of variability of yields among the three
watersheds indicates that differences in land uses are small enough that few distinctions can
be made between watersheds. Overall, storm runoff contributed more than one-half of the mean
annual yields for chemical oxygen demand, suspended solids, most of the selected nutrient
constituents, and total recoverable copper, lead, and zinc. Large yields of chemical oxygen
demand, suspended solids, and total recoverable metals during storm runoff from one of the
watersheds are probably related to the erosion of exposed soils at construction sites within
the watershed. Low yields of suspended solids and total recoverable copper and zinc from
another watershed are probably related to retention-storage effects from lakes upstream from
the sampling site.

Potential contaminants in storm runoff from urban areas may degrade local water quality and
downstream receiving water even though concentrations of many contaminants in runoff from
urban areas often are small compared to industrial and municipal wastewater discharges (U.S.
Environmental Protection Agency, 1996a). In response to concerns about the quality of storm
runoff from urban areas, the U.S. Environmental Protection Agency (EPA), under section 402 of
the Water Quality Act of 1987, currently (1998) requires that municipalities with a population
of 100,000 or greater, or facilities associated with industrial activities, obtain a National
Pollutant Discharge Elimination System (NPDES) permit and monitor the quality of their storm
runoff. Many large military installations are required to obtain a NPDES permit because of
industrial activities associated with the installation. Relatively small installations,
similar to Fort Leavenworth (population of about 6,200 in 1996; U.S. Army, Fort Leavenworth,
oral commun., 1997), are not required to obtain a NPDES permit. Nevertheless, Fort Leavenworth
is attempting to meet at least some of the NPDES requirements by monitoring the quality of
their storm runoff.

Following some of EPA's NPDES requirements, the U.S. Geological Survey (USGS), in cooperation
with the U.S. Army Environmental Office at Fort Leavenworth, Kansas, began a 2.5-year study in
1994 to:

Characterize the quantity and quality of water discharging during low-flow and
storm-runoff conditions at selected sampling sites that represent different
combinations of land uses at Fort Leavenworth. This characterization includes an
evaluation of water-quality constituent concentrations and loads at selected stream
sampling sites.

Determine if previously developed equations by Driver and Tasker (1990) for estimating
constituent loads and mean concentrations in urban stormwater can be used to reasonably
estimate loads and concentrations for urban watersheds in the Fort Leavenworth area.

Results of this study will provide improved understanding of characterization and evaluation
of water quality in urban areas similar to Fort Leavenworth.

The purpose of this report is to present information to assess stream water-quality conditions
and possible methods for anticipating future water-quality effects from storm runoff and
changes in land use. The report includes: (1) presentation of estimates of annual mean
concentrations, loads, and yields of selected water-quality constituents during low-flow and
storm-runoff conditions and (2) evaluation of previously developed procedures to estimate
loads and mean concentrations.

Fort Leavenworth is located in Leavenworth County, northeast Kansas, about 10 mi north of
Kansas City, Kansas, along the Kansas-Missouri State line (fig. 1). The fort is bounded along the
north and east sides by the Missouri River. The city of Leavenworth and U.S. Department of
Justice property (Leavenworth Federal Penitentiary) are adjacent to the south boundary, and
wooded acreage and farmland are found along the west boundary.

Fort Leavenworth was established in 1827 and is the oldest fort west of the Mississippi River
still in existence (Frontier Army Museum, Fort Leavenworth, oral commun., 1997). For 30 years
it was the chief base of operations for the frontier, providing a military buffer zone between
settlers and Native American tribes. During the 1830s and 1840s thousands of wagons bound for
the Oregon and Santa Fe Trails crossed the Missouri River and passed through the fort. Between
1846 and 1848, the fort was the outfitting post for the Army of the West during the war with
Mexico. The National Cemetery, dedicated by President Abraham Lincoln in 1862, has more than
19,000 veterans buried, representing every war America has participated in since 1912. In
1873, the U.S. Disciplinary Barracks (DB) was established, and today (1998) is the only
military maximum security facility. A school, which later became the Command and General Staff
College (CGSC), was established in 1881. CGSC is the most advanced school of military tactics
in the Army educational system, and today is the primary function at Fort Leavenworth.

Fort Leavenworth occupies about 9 mi² of land along the Missouri River. Most of the fort
was built on the uplands adjacent to the Missouri River. About 4 mi² are in the flat
bottoms of the Missouri River flood plain. The flood plain has soils of deep, silty-clay loam
that are nearly level and somewhat poorly drained (Zaresky and Boatright, 1977). The slope
within the flood plain is less then 1 percent. Soils on the upland, rolling hills were formed
in loess and are a silt loam and silty-clay loam. The soils along steep slopes and in the
upland areas are thick and well drained. The soils in the lowland areas of the rolling hills
are poor to moderately well drain and are thick. The slope in the hilly section of the fort
ranges from 4 to 35 percent. Land surfaces within the fort's boundary range from about 755 ft
above sea level at the Missouri River to about 1,080 ft above sea level on the highest ridge
along the west boundary (fig.
2).

The activities at Fort Leavenworth are atypical of activities at most Army installations.
There is almost no heavy equipment (tanks, artillery, or helicopters) at the installation. The
major activities at Fort Leavenworth are the CGSC, the DB, Sherman Army Airfield, and
associated administrative functions.

Land use at Fort Leavenworth is similar to a small city. The fort has single- and
multiple-family housing, with three elementary schools and one junior high school, shopping
centers, a hospital, bank, and a golf course. The remainder of the urban area consists of CGSC
buildings, DB buildings, Sherman Army Airfield, roads, parking lots, urban-open spaces, and
administration buildings. There are several small lakes at the fort; the two largest lakes are
Merritt and Smith Lakes near the center of the urban area. Agricultural and undisturbed native
grasses and forest areas surround the urban area.

A 1993 digital computer map provided by Fort Leavenworth was used to determine the areas of
land use and watersheds within and near the fort's boundary. Land uses were delineated by six
general classifications: (1) nonurban, (2) urban open area, (3) residential, (4) commercial,
(5) industrial, and (6) lakes or open-water areas. The areal distribution of the six land-use
classifications within the study area during 1993 is shown in
figure 3. Specific land uses for each
classification are as follows:

Urban open area--All open grassland or wooded areas within the urban part of the study
area, such as parks, a golf course, cemeteries, greenbelts along waterways, vacant
undeveloped land, and open tracts of land.

Residential--Single- and multiple-family housing.

Commercial--Schools, offices, retail businesses, a hospital, and a bank.

Industrial--Warehouses, an airfield, and a vehicle maintenance shop.

Forty-six percent of the land use within the study area in 1993 was nonurban. Urban open areas
were 26 percent of the land use in the study area. The remaining lands in the study area were
mostly residential and commercial areas, and less than 1 percent were classified as industrial.

The Fort Leavenworth area has a wide range of monthly temperature extremes and uneven rainfall
distribution throughout the year. Mean annual temperature and precipitation for 1961-90 at
Leavenworth, Kansas, is 56.6 °F and 40.5 in., respectively (National Oceanic and
Atmospheric Administration, NOAA, 1992). The mean air temperature for January is 27 °F and
for July is 76 °F. Seventy percent of the mean annual rainfall occurs during the warm
growing season, April through September.

Precipitation data from the NOAA precipitation gage in Leavenworth, Kansas, indicated that
monthly rainfall totals during the study period, May 1994 through September 1996, were mostly
less than the 30-year mean monthly totals with two notable exceptions
(fig. 4). Precipitation totals for May 1995 and
June 1996 were the largest ever recorded at that site for May and June since 1948 (Mary Knapp,
State Climatologist, Kansas State University, oral commun., 1997).

The main surface-water features in Leavenworth County are the Kansas and Missouri Rivers and
their tributaries. The west and south parts of Leavenworth County are drained by the Kansas
River and its tributaries. The width of the Kansas River Valley along the south boundary of
the county is slightly more than 1 mi. The east part of Leavenworth County drains into the
Missouri River and its tributaries. The Missouri River Valley is 2 to 3 mi wide in the
vicinity of the study area.

The study area is drained by Quarry and Corral Creeks and an unnamed tributary to the Missouri
River (fig. 2). Each stream
flows from the upland area of Fort Leavenworth, east to the Missouri River. Runoff within the
study area flows overland either into one of the three streams or through a storm-water
drainage system that consists of gutters, grates, and concrete pipes and then into one of the
streams. There are three lakes along the unnamed tributary-Merritt, Smith, and Fuller Lakes
(fig. 2).

The author expresses appreciation to Ronald Banks, Environmental Specialist, and the entire
Environmental Office at Fort Leavenworth, for assistance in coordinating the study and for
providing information about Fort Leavenworth.

Sampling sites were selected on the basis of the location of urban areas within the fort, the
size of the contributing watersheds, and the proximity of the Missouri River. Sites were
selected that would represent the maximum urban drainage area of the watersheds while
minimizing the effects of backwater from the Missouri River. Three sampling sites were
selected in open channels that drain three separate watersheds: (1) Quarry Creek at the
Missouri River (site 06820464, fig. 2), (2) unnamed tributary at Stimson Avenue, Fort Leavenworth
(site 06820468, fig. 2), and
(3) Corral Creek at Fort Leavenworth (site 06820472, fig. 2). Together, the three sites represent about 83
percent of Fort Leavenworth's urban area and about 38 percent of the fort's total area.
Sixty-two percent of the fort's impervious area is contained within the three watersheds
(fig. 3). A description of selected
land-use data for the three watersheds is listed in table 1.

Nonurban Urban open area Residential Commercial Industrial
Lakes or open water

70 14 <1 15 0 <1

06820468

Unnamed tributary at Stimson Avenue, Fort Leavenworth, Kansas

39°20'50" 94°54'42"

.67

54

Nonurban Urban open area Residential Commercial Industrial
Lakes or open water

2 58 13 24 1 2

06820472

Corral Creek at Fort Leavenworth, Kansas

39°20'09" 94°55'01"

1.91

13

Nonurban Urban open area Residential Commercial Industrial
Lakes or open water

45 23 20 11 <1 <1

1The sum of the land-use percentages may not equal 100 percent due to rounding
errors.

Site 06820464 (fig. 2) is
located on Quarry Creek 400 ft upstream from the Missouri River. Quarry Creek drains about
1.45 mi² (table 1) of the north, hilly part of Fort Leavenworth. The
natural stream channel for the upstream part of the watershed mostly drains nonurban and urban
open areas and includes some commercial areas. As the main stem of the stream flows northeast
towards the Missouri River flood plain, the stream channel is confined to an underground
concrete box culvert for about 1,700 ft (fig. 3). The main stem of Quarry Creek combines with a major tributary from the
northwest and flows south parallel to the train tracks and steep hills along the west bank and
a levee along the east bank. As the stream flows south, five corrugated steel pipes that drain
impervious areas of the watershed outfall along the west bank. The location of sampling site
06820464 was selected primarily to collect runoff and water-quality information from the
watershed, including the five outfalls draining into the stream. Some of the runoff within the
watershed is drained downstream from the sampling site. This location was ideal for collecting
representative runoff from nearly all the watershed; however, it had a high potential for
being affected by backwater from the Missouri River. When the stage of the Missouri River is
greater than the elevation of the sampling site, the water at the site becomes a mixture of
Missouri River water and water from the Quarry Creek watershed.

The Missouri River flood plain is adjacent to the eastern part of the Quarry Creek watershed
boundary (figs. 2 and
3). A levee surrounds the west part of
the flood plain where Sherman Army Airfield and several water-supply wells are located. The
levee helps prevent the Missouri River from flooding this section of Fort Leavenworth. Runoff
in the south part of this area flows towards a pump on the southwest part of the flood plain
near the levee. The water is pumped from the flood plain into Quarry Creek 30 ft upstream
from the sampling site on Quarry Creek.

Site 06820468 (fig. 2) is
located 2,000 ft upstream from the Missouri River at the intersection of an unnamed tributary
and Stimson Avenue. The drainage area upstream from the site is about 0.67 mi² of the
upland part of the fort adjacent to the Quarry Creek watershed. The unnamed tributary's
watershed includes three lakes near the center of the area. More than one-half of the drainage
area is urban open area (golf course and historical site), and 37 percent of the watershed is
classified as commercial and residential (CGCS and administrative buildings). The upstream
part of the watershed contains a golf course and some impervious, urban areas. Runoff from
this upstream area drains into Merritt Lake and subsequently into a 150-ft long pipe that
drains into Smith Lake. Some of the impervious and urban areas for the watershed drain
directly into Smith and Fuller Lakes. Seven storm-drainage pipes from nearby parking lots
outfall along the banks of the two lakes. Smith and Fuller Lakes are hydrologically connected.
Each lake drains separately into the unnamed tributary about 800 ft upstream from the sampling
site. Three outfalls, primarily draining impervious areas (parking lots and buildings),
discharge into the unnamed tributary between the lake outfalls and the sampling site.

The elevation of the unnamed tributary sampling site is about 4 ft higher than the elevation
of the Quarry Creek site. Therefore, the potential for the unnamed tributary sampling site to
be affected by backwater from the Missouri River is somewhat less than the backwater potential
at the Quarry Creek site.

Site 06820472 (fig. 2) is
located on Corral Creek about 2,200 ft upstream from the Missouri River. The drainage area
represented by this site is about 1.91 mi² of the Corral Creek watershed. The watershed
includes about 1.3 mi² of the southern, most hilly section of the fort and about 0.6
mi² of land that is outside the Fort Leavenworth boundary. The land use of the watershed
outside of the fort's boundary consists of commercial and agricultural areas associated with
Leavenworth Federal Penitentiary and a commercial area of the city of Leavenworth. The land
use of the watershed within the fort's boundary consists of mostly nonurban and urban open
areas and the largest residential area of the three watersheds. Runoff for most of the
impervious areas of the watershed flows through storm-drainage pipes and discharges at 43
locations along Corral Creek or its tributaries.

The main stem of Corral Creek begins in the high bluffs along the fort's west boundary. The
stream generally flows in an easterly direction and receives drainage from the large
residential area and from about one-half of the Leavenworth Federal Penitentiary area. The
contributing drainage area from the penitentiary is mostly nonurban. Downstream from the
penitentiary, Corral Creek combines with a large tributary that drains the residential area
north of the main stem. Land use along Corral Creek downstream from this confluence consists
of commercial, nonurban, and urban open areas. Some of the nonurban and urban open areas
include dense timber. Much of the nonurban land is pasture for cattle. A herd of about 25 cows
grazed upstream from the Corral Creek sampling site during the first 1.5 years of the study.
As observed during site visits, the cattle frequently stood in and near Corral Creek just
upstream from the sampling site during warm weather. During the winter of 1996, the cattle
were removed from this area of the watershed.

The Corral Creek watershed contained two large construction sites during the study period.
Vegetation was cleared from these sites exposing soils for construction of buildings, parking
lots, and access roads.

Streamflow and water-quality data were collected from May 1994 through September 1996 to
characterize the water quality and evaluate procedures for estimating mean storm-runoff loads
for selected properties and constituents in streams draining Fort Leavenworth. Samples were
collected manually during low flow and with automatic samplers during storm runoff so that
water quality could be characterized for both flow conditions. Precipitation data were
collected at two of the three sampling sites (fig. 2).

Continuous stream-stage (water-surface elevation) data were collected at the three sampling
sites from May 1994 through September 1996 with USGS stream-gaging equipment. Each sampling
site was equipped with a Sutron model 8200 or 8210 data logger/transmitter. The logger was
programmed to collect stream-stage data according to rate of change in stream stage.
Stream-stage data were collected hourly during steady (rate of change less than 0.01 ft/hr)
low-flow conditions and as frequently as every 5-minutes during rapid stream-stage,
storm-runoff fluctuations (rate of change greater than 0.01 ft/min). The stream stage was
measured with a gas-purge system and a nonsubmersible, pressure transducer. The gas-purge
system reacted to changes in stream stage with proportional changes in pressure. The pressure
transducer measured the pressure in the gas-purge system and converted the pressure reading to
a reading of unit length (feet). The converted measurements were stored by the data logger to
await subsequent transmittal and determination of how much the stream stage was changing and
to determine whether to log the reading or wait for the next measurement. Streamflow
measurements (Rantz and others, 1992) were made manually throughout the study period to
develop, verify, and adjust stage-streamflow relationships that were used to calculate
instantaneous and daily mean streamflow values according to procedures presented in Kennedy
(1983). Daily mean streamflow is presented in table 7
in the "Supplemental Information" section of this report. Hydrographs for the three sites are
shown in figure 5.

Annual streamflow was analyzed and separated into low flow and storm runoff to characterize
both types of conditions. Low flow for this study was defined as streamflow that was
unaffected by storm runoff. For daily mean streamflow affected by storm runoff, a low-flow
component was estimated on the basis of the previous and the following mean daily streamflows
that were not affected by storm runoff. Streamflow data for the period of May through
September 1994 is included in table 7 in the
"Supplemental Information" section of this report and shown in
figure 5 but only data for October 1994 through September 1996 were used
to compute mean annual flow volume shown in table 2. Total low flow for
the three sites during 1995 and 1996 was about 1,840 acre-ft or one-half of the total flow
(3,700 acre-ft, table 2).

Daily mean streamflow for all three sampling sites was estimated on some days during the
summers of 1995 and 1996 due to backwater effects from high flow of the Missouri River and
during the winter months when ice cover affected the stream-stage relation. During periods of
backwater, the stage of the Missouri River was high enough to alter the stream-stage relation
at the three sampling sites. Therefore, daily mean streamflow during periods of backwater was
estimated using previous and subsequent precipitation and flow data collected at these sites.
During cold periods when ice cover affected the stream-stage relation, the daily streamflows
were estimated on the basis of precipitation and temperature data and the daily mean
streamflow prior to and following the ice-affected period. Estimated daily mean streamflow at
the three sampling sites are identified in table 7 in
the "Supplemental Information" section of this report with an "e" next to the daily mean
value. Estimated daily mean values accounted for 19 to 25 weeks of the total study period and
29 to 49 percent of the total flow for the study. Samples were not collected during periods
when streamflow was estimated.

Streamflow data for Quarry Creek represent flow from the Quarry Creek watershed as well as
flow from the levee pump 30 ft upstream from the sampling site. This pump moves water from
inside the leveed area of the fort into Quarry Creek. The pump was activated up to three or
four times a day, depending on the amount of ponded water inside the levee near the pump
intake. When a large volume of water was present, the pump would run for 15 to 60 minutes,
discharging between 1.5 and 5.0 ft³/s.

Rain gages were installed at the Quarry Creek and Corral Creek sampling sites
(fig. 2). Rainfall
amounts for each storm sampled are listed in table 3. The primary
purpose of the rain gages was to provide the data loggers with rainfall information to
determine if a storm was large enough to be sampled. Overhead clearance at each rain-gage site
was not ideal. Nearby trees may have obstructed the openings of the rain gages; therefore, the
recorded rainfall data may underestimate actual rainfall amounts.

Low-flow samples for the analysis of selected inorganic water-quality constituents were
obtained manually using a 1-L Teflon bottle dipped into the centroid of flow of the stream.
The dipped samples were composited in a 9-L polyethylene churn splitter, as described in
Horowitz and others (1994), and split into subsamples for analysis of inorganic compounds.
Bottles designated for analysis of organic constituents were individually filled onsite.
Samples were preserved and sent to the USGS National Water-Quality Laboratory (NWQL) in
Arvada, Colorado, for analysis according to methods presented in Fishman (1993).

The storm-runoff samples that were collected during the study represented a wide range of
storm characteristics and antecedent conditions. Rainfall amounts for each storm sampled were
always more than 0.10 in. The largest rainfall amount for a sampled storm was 1.86 in. on July
19, 1995 (table 3). Durations for the storms sampled ranged from 35
minutes to 6.5 hours. To follow NPDES sampling guidelines, attempts were made to sample storms
with 3-day antecedent rainfall of less than 0.10 in. About one-half the storm-runoff samples
collected met this condition.

Storm-runoff samples were collected from May 1995 through August 1996 using ISCO model 3700
automatic-pumping samplers. The samplers consisted of Teflon-lined, water-intake tubing, a
stainless-steel screen (hereinafter referred to as the screen) attached to the stream end of
the intake tubing, a peristaltic pump, and four 1-gal glass sample jars. The automatic
sampler, on a signal from the Sutron data logger, pumped water from the stream through the
intake tubing into the glass sample jars. The data logger was programmed to monitor rainfall
and streamflow to determine when to signal the automatic sampler to collect a sample. After a
pre-assumed amount of rain and rainfall rate were reached, the data logger used a programmed,
stream-stage relation to calculate streamflow. The data logger was programmed to signal the
automatic sampler once a pre-assumed volume of runoff was recorded. Because samples were
collected at equal streamflow increments (pre-assumed volumes), each discrete 1-gal sample was
flow weighted. For the purpose of laboratory analyses, these discrete samples were composited
into one flow-weighted composite sample.

The final flow-weighted composite sample represented a pre-assumed storm-runoff volume.
However, storm-runoff volumes varied substantially between storms which produced differences
in sample representation. For an event where the total storm-runoff volume was greater than
the pre-assumed volume, the composite sample represented only part of the total storm-runoff
volume (table 3). Water-quality constituent concentrations determined
from a composite sample collected in this manner represented mean concentrations for that part
of the storm sampled and not the entire storm. In a case where the total storm-runoff volume
was less than the pre-assumed total storm volume, then the resulting composite sample
represented the entire storm runoff; however, not all four sample jars would be filled. This
reduction in sample volume, reduced the number of analyses from the full suite of 272
properties and constituents.

Storm-runoff samples were transported to the laboratory at the USGS in Lawrence, Kansas, and
split into subsamples using a Teflon cone splitter (Horowitz and others, 1994) and a
polyethylene churn splitter. The cone splitter was used to initially split the flow-weighted,
discrete 1-gal samples into subsamples for analysis of organic and inorganic constituents.
From these two subsamples, samples for analysis of organic compounds were split using the cone
splitter, and samples for analysis of inorganic compounds were split using the churn splitter.
Samples were preserved and sent to the NWQL in Arvada, Colorado, for analysis.

All equipment used to collect water samples were cleaned and placed in plastic bags prior to
use. Glass and Teflon sample bottles, Teflon-lined tubing, churn splitter, and cone splitter
were cleaned using a 2.5-percent nonphosphate detergent solution, rinsed using deionized
water, soaked for 30 minutes in a 10-percent hydrochloric acid solution, and rinsed with
organic-free water. The screen at the stream end of the intake tubing was cleaned frequently
by removing debris and algae accumulation.

Quality-control (QC) samples were collected and analyzed to assure the integrity of the
water-quality data for this study. Analytical results from the QC samples helped determine if
procedures used for collection and processing of samples maintained representativeness. Six QC
samples were collected during this study-four equipment blanks and two replicates.

Equipment-blank samples were collected and processed as if they were actual storm-runoff
samples to inspect the cleanliness of the equipment. Blank water (highly purified, free of
contamination) was passed through all or some of the equipment used to collect storm-runoff
samples. Blank samples were processed following the identical procedures used to process
storm-runoff samples and sent to the NWQL for analysis. Equipment-blank samples were labeled
QC-1, QC-2, QC-3, and QC-4, and the results of analyses of these samples are included in
table 8 in the "Supplemental Information" section of this
report. Samples QC-1 and QC-2 were collected and processed exactly like a storm-runoff sample
using all the sample-collection and processing equipment. Blank water for sample QC-3 was
passed through all the sample-collection and processing equipment, except the automatic
sampler was without the screen at the end of the Teflon-lined tubing. Sample QC-4 was blank
water passed through the sample-processing equipment only. Samples that passed through all of
the equipment were compared to samples that were passed through just some of the equipment to
determine if a specific piece or group of equipment was a possible source of contamination.

Most of the values and concentrations of constituents in equipment blanks were less than the
analytical reporting level, indicating there was little contamination from the sampling and/or
processing equipment. Silica and total organic carbon were detected in all of the blank
samples (table 8 in the "Supplemental Information" section
of this report). None of the concentrations were more than five times the analytical reporting
level. A possible source for the silica and total organic carbon concentrations is
contaminated blank water. The concentrations of silica and total organic carbon in blank
samples probably are insignificant relative to environmental concentrations that generally are
one to two orders of magnitude larger (table 8).

Samples QC-1, 2, and 3 had detectable concentrations of calcium and iron. These constituents
are found in natural water samples at concentrations 100 to 1,000 times the largest
concentration detected in the blank samples. The concentrations detected may be from some
small amounts of water or residue inside the pump intake tubing that may have contaminated the
blank samples.

Suspended solids were detected in samples QC-1 and 2 at concentrations of 3 and 6 mg/L,
respectively. The source for these concentrations may be the screen at the stream end of the
intake tubing. The blank samples collected without the screen in place had no detections of
suspended solids.

Magnesium, manganese, and mercury were detected in sample QC-1. Magnesium and manganese
concentrations were at the analytical reporting level for the constituents, and the mercury
concentration was three times the analytical reporting level. These constituents may have been
contributed from the screen or the pump tubing. Samples QC-2 (tubing with screen) and QC-3
(tubing without screen) had no detections of these constituents.

Replicate samples of low flow were collected concurrently to determine variability in
sample-collection and processing techniques. Variability in concentrations of constituents
between samples can occur if collection and/or processing techniques differ between samples.
Large differences between sample concentrations for some constituents can reflect variability
in either or both sample-collection and processing techniques. Minor differences between
samples assure that any variability in sample-collection or processing techniques are
insufficient to affect environmental concentrations.

The percentage difference for values and concentrations in concurrent replicate samples was
less than 5 percent for all but 14 constituents. The range of differences in the 14
constituents was from 5.3 to 71.4 percent. Most of the variability in the concurrent replicate
samples was hundredths of a milligram per liter or less and probably within the analytical
variability of the laboratory's measurements. The largest variation occurred between samples
collected for oil and grease. The variability is most likely due to the sample-collection
technique. When collecting samples for oil and grease, a sample bottle is dipped into the
stream, filled, preserved, and capped. Because it was impossible to collect two samples at
once from the exact same location in the stream, samples were collected one at a time,
concurrently. This method of collection is the most likely reason for the variability between
the samples.

Measurements of specific conductance and pH were occasionally made during sample collection or
hours after sample collection during sample processing at the laboratory in Lawrence, Kansas.
Measurements of specific conductance and pH were usually made at the NWQL within days or weeks
of sample collection. The variability between the values measured in Lawrence and the values
measured at the NWQL ranged from about 1 to 23 percent difference. Probably the most
significant explanation for this variability is the time difference of when the samples were
measured for specific conductance and pH. The measurements made in Lawrence were within hours
of collection when the sample was still approaching a chemical equilibrium. The measurements
made at the NWQL were days or weeks after sample collection when the sample had had more time
to reached a chemical equilibrium, altering specific conductance and pH.

Sources of streamflow and land-use activities within a watershed typically are determining
factors in resulting concentrations of water-quality constituents in streams. The major
components of streamflow are ground water and surface runoff. Ground water contributes to
streamflow any time the elevation of the stream is less than the elevation of the ground-water
surface. During periods of low flow, ground water is the primary source of streamflow;
therefore, the water-quality constituent concentrations in streamflow reflect concentrations
in ground water. When the elevation of the stream is greater than the ground-water surface
elevation, some water flows from the stream into the ground water. This may occur during
storms and backwater conditions. The primary source of streamflow during and immediately
following a storm is surface-water runoff. Rainfall on impervious and saturated surfaces
within the study area eventually flows into one of the three study streams. As the water flows
across these surfaces, contaminants can be transported into the streams. Depending on land
use, different contaminants can accumulate during dry periods. For example, on paved surfaces,
contaminants from automobiles and trucks may accumulate until a large enough storm occurs to
wash the contaminants from the pavement and into the streams.

Thirty-nine water-quality samples were collected from August 1994 through September 1996--12
low-flow samples, 21 storm-runoff samples, and 6 quality-control (QC) samples. Samples were
analyzed for as many as 272 properties and constituents.
Table 8 in the "Supplemental Information" section of this report lists the properties
measured and inorganic, radionuclide, and detected organic constituents.
Table 9 in the "Supplemental Information" section of this
report lists all the organic constituents analyzed and their analytical reporting level. Some
of the properties measured and constituents analyzed included specific conductance, pH,
chemical oxygen demand, major ions, dissolved and suspended solids, nutrients, bacteria, total
recoverable metals, radionuclides, total organic carbon, phenols, oil and grease, volatile
organic compounds, acid-base/neutral organic compounds, and pesticides. Although the water in
these streams is not used by humans for drinking, concentrations of the constituents were
compared to the most stringent Federal regulations, the Maximum Contaminant Levels (MCLs) and
Secondary Maximum Contaminant Levels (SMCLs) established by EPA drinking-water regulations
(U.S. Environmental Protection Agency, 1996b).

Characterization of water quality during low flow was necessary to establish a basis for
assessing the water-quality changes caused by storm runoff. Low-flow samples were collected
during August or September in each of the years 1994, 1995, and 1996 to represent summer
low-flow conditions and during March 1996 to represent late winter or early spring low-flow
conditions. Two water samples from Corral Creek were collected when cattle were immediately
upstream from the sampling site, and two samples were collected after the cattle were gone. In
February 1996, stream conditions in the unnamed tributary had changed considerably. The water
at the sampling site had an odor, and the stream bottom was covered with a brown organic
deposit. The condition continued until April 1996 when a damaged, municipal sewer pipe was
repaired. The damaged pipe was located along the southwest bank of the unnamed tributary about
750 ft upstream from the sampling site and just downstream from the lake outfalls. The top of
the pipe was damaged, so it leaked only when the pipe was full. The damaged pipe was
intermittently discharging untreated municipal sewage into the unnamed tributary. A low-flow
water sample was collected from the unnamed tributary during March 1996, when the broken,
municipal sewer pipe was discharging into the stream. Because of the unusual water-quality
conditions during the period of the broken sewer pipe, this sample was not used for
calculating selected, low-flow, mean constituent concentrations in water from the unnamed
tributary (table 4).

Specific conductance and pH were measured onsite and at the NWQL for each low-flow water
sample. Specific conductance and pH measured at the NWQL varied less than 6 percent from the
onsite measurements. Laboratory measurements of specific conductance ranged from 503 to 1,040
µS/cm at 25 °C, and pH ranged from 7.2 to 8.2 standard units
(table 4). The largest mean measurements of specific
conductance and pH were in samples from Quarry Creek and were 1,010 µS/cm at 25 °C
and 7.9 standard units. The lowest mean measurements of specific conductance and pH were in
samples from the unnamed tributary at 576 µS/cm at 25 °C and 7.3 standard units.
All of the pH measurements were within the SMCL range of 6.5 to 8.5 (U.S. Environmental
Protection Agency, 1996b).

Determination of chemical oxygen demand is one of several methods to quantitatively evaluate
the organic contamination load (Hem, 1985). Chemical oxygen demand is the amount of oxygen
required for chemical oxidation of organic matter to carbon dioxide and water (Hammer, 1986).
Generally speaking, the greater the chemical oxygen demand the greater the organic
contamination load. For instance, the maximum chemical oxygen demand concentration was 100
mg/L (more than two times the next largest low-flow concentration at any sampling site) in
water from the sampling site on the unnamed tributary when untreated municipal sewage was
discharging into the stream (table 8). Mean concentrations
of chemical oxygen demand for low-flow samples were 13 mg/L for water from Quarry Creek, 23
mg/L for water from the unnamed tributary, and 23 mg/L for water from Corral Creek
(table 4).

Low-flow concentrations of major ions were generally largest in water samples from Quarry
Creek. The largest concentrations of calcium, magnesium, sulfate, and chloride were measured
in water samples collected from Quarry Creek (table 8).
The largest concentrations of sodium and potassium were in samples collected from Corral
Creek. A water sample from the unnamed tributary had the largest concentration of silica. None
of the concentrations exceeded the MCLs or the SMCLs (U.S. Environmental Protection Agency,
1996b) for sulfate (250 mg/L), chloride (250 mg/L), or fluoride (4.0 mg/L).

Dissolved and suspended solids concentrations in low-flow water samples varied considerably
between sampling sites. Dissolved solids concentrations ranged from 298 mg/L in water from the
unnamed tributary to 702 mg/L in water from Quarry Creek
(table 4). The mean dissolved solids concentration in
samples from Quarry Creek (669 mg/L) was 55 percent larger than the mean concentrations in
samples from the unnamed tributary and Corral Creek (433 and 432 mg/L, respectively) and 34
percent larger than the SMCL (500 mg/L). Mean concentrations of suspended solids varied in
samples from each site-22 mg/L in water from Quarry Creek, 7 mg/L in water from the unnamed
tributary, and 38 mg/L in water from Corral Creek. The largest discrete suspended solids
concentration, 92 mg/L, was measured in water from Corral Creek when cattle were present, and
the smallest concentration, less than 1 mg/L, was measured in water from Corral Creek when no
cattle were present. These data appear to indicate that cattle may have disturbed streambed
sediment and bank material and subsequently increased the amount of suspended material in the
water. This interpretation should be viewed with caution for the number of samples collected
(four) may be too small for definitive evaluation.

Low-flow mean concentrations of total nitrogen (calculated by adding total ammonia plus
organic nitrogen and total nitrite plus nitrate) and total and dissolved phosphorus were
largest in water samples from the unnamed tributary. The mean concentration of total ammonia
plus organic nitrogen as nitrogen was largest in water from Corral Creek. The mean
concentration of total ammonia plus organic nitrogen as nitrogen for the two water samples
collected from Corral Creek when cattle were present in and along the stream near the sampling
site was 2.3 mg/L. In contrast, the mean concentration of the two samples collected in 1996,
when no cattle were present in these areas, was 0.25 mg/L. Although this comparison seems to
indicate an effect on nutrient concentrations from cattle with direct access to the stream,
the number of samples collected (four) may be too small for definite evaluation. The water
sample collected on March 28, 1996, from the unnamed tributary had the largest concentrations
of dissolved ammonia, total ammonia plus organic nitrogen as nitrogen, total phosphorus,
dissolved phosphorus and dissolved orthophosphorus of all the low-flow samples
(table 8). None of the samples exceed the 10-mg/L MCL
(U.S. Environmental Protection Agency, 1996b) for dissolved nitrite plus nitrate as nitrogen.

Bacteria samples were collected from sampling sites only during low flow. Fecal coliform and
fecal streptococci residing in the intestinal tract of humans and other warmblooded animals
are excreted in large numbers in feces (Hammer, 1986). Untreated domestic wastewater generally
may contain more than 3 million col/100 mL [colonies (organisms) per 100 milliliters of water]
of fecal coliform. The largest counts of fecal coliform and fecal streptococci were measured
in samples from the unnamed tributary during March 1996 when untreated municipal sewage leaked
into the stream. The fecal coliform count was about 2,500,000 col/100 mL (100 times the next
largest count), and the fecal streptococci count was about 42,000 col/100 mL (six times the
next largest count) (table 8). The range for fecal
coliform counts in low-flow water samples (not including nonideal counts) was 89 to 14,000
col/100 mL in samples from Quarry Creek, 2,100 to 2,500,000 col/100 mL in samples from the
unnamed tributary, and 1,900 to 24,000 col/100 mL in samples from Corral Creek. Fecal
streptococci counts ranged from 135 to 12,000 col/100 mL in samples from Quarry Creek, 5,400
to 42,000 col/100 mL in samples from the unnamed tributary, and less than 1,500 to 6,700
col/100 mL in samples from Corral Creek. Samples collected from Corral Creek averaged 18,000
col/ 100 mL fecal coliform and 4,600 col/100 mL fecal streptococci when cattle were within the
drainage area and 980 col/100 mL fecal coliform and 1,500 col/100 mL fecal streptococci when
they were not. Although this comparison seems to indicate that cattle with direct access to
the stream may affect the amount of instream bacteria, the number of samples collected (four)
may be too small for definitive evaluation.

Concentrations of total recoverable metals such as antimony, arsenic, beryllium, cadmium,
chromium, copper, lead, mercury, nickel, selenium, silver, thallium, and zinc were small (less
than 50 µg/L) in low-flow samples; in fact, all concentrations for beryllium, cadmium,
mercury, silver, and thallium were less than analytical reporting levels. Concentrations of
total recoverable manganese for all three sites ranged from 60 to 570 µg/L. None of the
low-flow concentrations for total recoverable metals exceeded MCL or SMCL values established
by EPA (U.S. Environmental Protection Agency, 1996b).

A sample for radionuclide analysis was collected from each site during low flow. The only
radionuclide detections were for dissolved gross alpha (6.5 µg/L) in water from Corral
Creek and dissolved gross beta (7.9 pCi/L) in water from the unnamed tributary.

Total organic carbon concentrations in water from all three sampling sites ranged from 3.2 to
10 mg/L for samples not affected by sewer leakage. The mean concentration of total organic
carbon was largest (5.9 mg/L) for samples from Corral Creek. Mean concentrations of total
organic carbon in water from Quarry Creek and the unnamed tributary were 4.0 and 5.2 mg/L,
respectively. A sample collected from the unnamed tributary in March 1996 (during the period
of sewer leakage) was 29 mg/L.

Total phenols were detected in at least one low-flow water sample from each of the three
sampling sites, ranging in concentration from less than 1 to 15 µg/L
(table 8). The two largest concentrations were 15 and 7
µg/L in samples from Corral Creek. There were two water samples with no detection of
phenols from Quarry and Corral Creeks and three samples with no detection of phenols from the
unnamed tributary. The only detection of phenols in samples from the unnamed tributary
occurred during the period of sewer leakage. The Corral Creek watershed has the only
substantial percentage of industrial land use of the three watersheds. Some industrial
activities potentially can contribute to phenol concentrations in surface water.

Oil and grease were detected in two low-flow samples from the unnamed tributary. A
concentration of 5 mg/L was detected in the sample collected when sewage was leaking into the
stream, and a concentration of 3 mg/L was detected in the replicate sample collected in August
1996. Oil and grease concentrtions were less than analytical reporting levels for all other
samples.

Two volatile organic compounds where detected in low-flow water samples. Chloroform was
detected in whole-water samples from the Quarry Creek and Corral Creek sampling sites during
March 1996; concentrations were 0.2 and 0.5 µg/L, respectively. Tetrachloroethylene was
detected at 0.3 µg/L in the March 1996 sample from Quarry Creek.

No acid-base/neutral organic compounds were detected in any of the 12 low-flow samples
collected. Eight pesticides were detected in low-flow samples. These include atrazine;
chlorpyrifos; 2,4-D; p,p' DDD; DDE; malathion; prometon; and simazine. Atrazine, prometon, and
simazine were detected in samples from all three sampling sites. Concentrations of 2,4-D were
detected in samples from the unnamed tributary and Corral Creek. Malathion was detected in
samples from Quarry Creek and the unnamed tributary. Chlorpyrifos was detected in a sample
from the unnamed tributary, and p,p' DDD was detected in samples from Quarry Creek. None of
the pesticide concentrations exceeded the MCL values established by EPA (U.S. Environmental
Protection Agency, 1996b).

Selected properties and concentrations of constituents in storm-runoff streamflow were
determined to assess the changes in water quality of receiving streams caused by storm runoff.
Storm-runoff samples were collected in 1995 and 1996 during three seasons and during unusual
conditions that may have affected storm-runoff constituent concentrations. Eleven samples were
collected during the spring, eight during the summer, and two during the fall. Cattle were
present at and near the Corral Creek sampling site during the collection of the first three
storm-runoff samples. The storm-runoff sample collected August 19, 1996, at the Quarry Creek
sampling site was affected by pump discharge from the adjacent Missouri River levee
(fig. 2) and,
therefore, was not included in the calculation of water-quality constituent concentration mean
values (table 5).

Mean measurements of specific conductance measured at the NWQL ranged from 157 µS/cm at
25 °C in water from the unnamed tributary to 743 µS/cm at 25 °C in water from
Quarry Creek (table 5). Measurements of pH varied little
from site to site, ranging from 6.9 to 7.7 standard units. Mean measurements of specific
conductance and pH in storm-runoff samples were smaller than mean measurements in low-flow
samples. All pH measurements were within the SMCL range of 6.5 to 8.5 (U.S. Environmental
Protection Agency, 1996b).

Mean concentrations of chemical oxygen demand in storm samples were largest in samples from
Corral Creek, 100 mg/L. Mean concentrations in water from Quarry Creek and the unnamed
tributary were 68 and 38 mg/L, respectively. Mean storm-runoff concentrations were larger than
mean low-flow sample concentrations in water from all sampling sites, indicating that storm
runoff is contributing a larger concentration of chemical oxygen demand compared to low-flow
concentrations, as shown in figure 6.

The largest concentrations of major ions were in samples from Quarry Creek. Overall,
concentrations of major ions in storm-runoff samples were smaller than concentrations in
low-flow samples (fig.
6). None of the concentrations exceeded the MCL or the SMCL (U.S. Environmental Protection
Agency, 1996b) for sulfate, chloride, or fluoride
(table 8).

Not all storm-runoff samples were analyzed for dissolved solids because of insufficient sample
volume. Three of the six storm-runoff samples from Quarry Creek and one of the six samples
from the unnamed tributary were not analyzed for dissolved solids. Of the samples from the
three sites for which dissolved solids were analyzed, concentrations ranged from 46 to 480
mg/L among samples. Maximum concentrations in samples from Quarry Creek, the unnamed
tributary, and Corral Creek were 480, 142, and 236 mg/L, respectively. Mean concentrations of
dissolved solids in storm-runoff samples were at least twice the mean concentrations in
low-flow samples at each of the three sites (fig. 6). None of the concentrations exceeded the SMCL of 500 mg/L (U.S.
Environmental Protection Agency, 1996b).

Concentrations of suspended solids in storm-runoff samples were largest in water from Corral
Creek. The mean concentration of suspended solids was 1,645 mg/L
(table 5), which was more than three times the mean
concentration in samples from Quarry Creek (496 mg/L) and more than five times the mean
concentration in samples from the unnamed tributary (304 mg/L). A major source for suspended
solids in water from Corral Creek may have been areas of exposed soil at the construction
sites within the watershed. Mean concentrations of suspended solids in storm-runoff samples
were at least 24 times larger than the mean concentrations in low-flow samples, indicating
that storm runoff greatly contributes to suspended solids concentrations.

Mean concentration of dissolved nitrite plus nitrate as nitrogen, total ammonia plus organic
nitrogen as nitrogen, and total and dissolved phosphorus in storm runoff varied among sampling
sites. Mean concentrations for most nutrient constituents in water samples from Quarry Creek
were larger than or nearly equal to the mean concentrations in water samples from the unnamed
tributary and Corral Creek. Large nutrient concentrations in the Quarry Creek samples could be
associated with the fact that the watershed has the largest percentage of nonurban land use of
the three watersheds. Common activities related to nonurban land use are agricultural
application of fertilizers and livestock grazing, both of which can contribute to nutrient
concentrations in storm runoff. Mean concentrations of all four selected nutrient constituents
in storm-runoff samples from Corral Creek were larger than or equal to mean concentrations in
low-flow samples (fig.
6). In storm-runoff samples from Quarry Creek, three of the four selected nutrient
constituents had mean concentrations larger than mean low-flow concentrations. Mean
concentrations of total nitrogen and total phosphorus in samples from the unnamed tributary
were larger during low flow than during storm runoff (table
5). All the concentrations of dissolved nitrite plus nitrate as nitrogen were less than
the 10-mg/L MCL (U.S. Environmental Protection Agency, 1996b).

Samples of water for analyses of fecal coliform and fecal streptococci bacteria were not
collected during storm-runoff conditions. The sample-collection technique using the automatic
sampler is such that the samples collected could not be used for bacteria analysis because of
potential cross contamination of the samples. The automatic sampler pumps water through
Teflon-lined tubing and into a glass bottle. Neither the tubing nor the bottles were
autoclaved as part of the cleaning process; therefore, the samples would not accurately
represent the number of bacteria in the streamwater.

Total recoverable metals such as copper, iron, lead, manganese, and zinc in storm-runoff
samples from all three sampling sites were detected at concentrations larger than analytical
reporting levels. Copper concentrations in all water samples from all sites ranged from 5 to
58 µg/L (table 5), the smallest in samples from the
unnamed tributary and the largest in samples from Corral Creek. Samples from Corral Creek also
had the largest mean concentrations of copper, iron, lead, manganese, and zinc, at 29, 26,000,
64, 1,900, and 244 µg/L, respectively. Samples from Quarry Creek and the unnamed
tributary had mean concentrations for copper of 20 and 8 µg/L, for iron of 10,000 and
15,000 µg/L, for lead of 41 and 43 µg/L, for manganese of 1,300 and 540
µg/L, and for zinc of 150 and 100 µg/L, respectively. Cadmium concentrations were
less than the analytical reporting level (1.0 µg/L) for one-half the water samples from
Quarry Creek, all of the water samples from the unnamed tributary, and two of the eight water
samples from Corral Creek (table 5). The largest cadmium
concentration was 3 µg/L in water from Corral Creek. Concentrations of total recoverable
metals in storm-runoff samples were much larger than concentrations determined in low-flow
samples. The smallest storm-runoff concentrations of total recoverable copper, iron, lead, and
zinc were equal to or larger than the maximum low-flow concentrations. None of the MCL or SMCL
values established by the EPA (U.S. Environmental Protection Agency, 1996b) were exceeded for
copper, lead, and zinc. Concentrations for iron and manganese in all the storm samples were
larger than the SMCL values established by the EPA (U.S. Environmental Protection Agency,
1996b) (300 µg/L for iron and 50 mg/L for manganese).

Three storm-runoff samples from Corral Creek were analyzed for dissolved gross alpha and
dissolved gross beta concentrations (table 8). Of the
three storm samples, dissolved gross alpha and beta were each detected twice. Gross alpha was
detected at 3.1 and 6.8 mµg/L, and gross beta was detected at 4.2 and 4.9 pCi/L.

Total organic carbon concentrations in water from all three sampling sites ranged from 7.1 to
56 mg/L (table 5). Mean concentrations of total organic
carbon in storm-runoff samples were 22 mg/L from Quarry Creek, 11 mg/L from the unnamed
tributary, and 34 mg/L from Corral Creek. Mean storm-runoff concentrations of total organic
carbon were at least two times larger than the mean low-flow concentrations.

Total phenols were detected in storm runoff from all three sampling sites, ranging in
concentration from less than 1 to 5 µg/L (table 8).
Industrial activities are a potential source of phenols. During storm runoff, phenols can be
mobilized by the runoff and result in increased concentrations in surface water. The Corral
Creek watershed is the only watershed with a substantial percentage of industrial land use.
Total phenols were detected at about the same frequency in storm-runoff samples as in low-flow
samples and in slightly smaller concentrations.

Oil and grease were detected at concentrations larger than 1 mg/L in at least one storm-runoff
sample from each of the three sampling sites (table 8).
In storm-runoff samples from Quarry Creek, the detected oil and grease concentration was 3
mg/L, in samples from the unnamed tributary it was 11 mg/L, and in samples from Corral Creek
they were 2 and 4 mg/L. Storm-runoff and low-flow samples had concentrations that were less
than or slightly more than the 1-mg/L analytical reporting level, indicating that oil and
grease concentrations were small during both streamflow conditions.

Samples for analysis of volatile organic compounds were collected during three storms at the
unnamed tributary. Concentrations of volatile organic compounds were not greater than the
analytical reporting levels (table 9 in the "Supplemental
Information" section) in any of the three storm-runoff samples. Storm-runoff samples collected
from all three sampling sites for analysis of base-neutral/acid organic compounds had
concentrations less than analytical reporting levels for base-neutral/acid constituents listed
in table 9 in the "Supplemental Information" section.

Fifteen pesticides were detected in the storm-runoff samples collected from all three sampling
sites (table 8). In samples from Quarry Creek, p,p' DDD;
DDE; p,p' DDE; p,p' DDT; malathion, and 2,4-D were detected in more than one-half of the
samples collected. More than one-half of the samples collected from the unnamed tributary had
detections of DDE; p,p' DDT; malathion; and 2,4-D. Chlordane, chlorpyrifos, Diazinon,
malathion, and 2,4-D were detected in more than one-half the samples collected from Corral
Creek. A sample collected from Quarry Creek on August 22, 1996, was the only sample without a
detection of 2,4-D.

DDT was banned from use in the 1970s, yet DDT and derivatives of DDT were detected in water
samples. The presence of these organochlorine compounds some 20 years later indicates the
persistence of DDT. None of the pesticide concentrations exceeded the MCL values established
by EPA drinking-water regulations (U.S. Environmental Protection Agency, 1996b).

The load (mass) of a water-quality constituent in a stream is a function of the concentration
and the streamflow. An examination of annual constituent loads in water from the three
sampling sites at Fort Leavenworth indicates the mass contribution of constituents by each
watershed to the receiving stream. Examination of constituent yields (mass per unit area) for
each site enables comparisons of normalized watershed contributions and possibly identifies
differences in contributions as a function of land use. Loads and yields were calculated for
this study using water-quality data for September 1994 through August 1996 and streamflow data
for water years 1995 and 1996.

NPDES permitting requires estimation of annual loads for 12 properties and constituents. For
this study, 11 of the 12 constituents required by NPDES permitting were analyzed. The 11
constituents analyzed were chemical oxygen demand, dissolved solids, suspended solids, total
ammonia plus organic nitrogen as nitrogen, total nitrogen, total phosphorus, dissolved
phosphorus, total recoverable cadmium, total recoverable copper, total recoverable lead, and
total recoverable zinc. The constituent required for NPDES permitting but not sampled for in
this study was 5-day biological oxygen demand. Samples for determining biological oxygen
demand were not collected because of an inability to analyze samples within 24 hours of sample
collection as required by sample-processing protocols. Total recoverable cadmium
concentrations determined during this study were mostly less than the analytical reporting
level (table 8); therefore, loads and yields were not
estimated for total recoverable cadmium.

Mean annual loads of selected constituents for each site were estimated from a summation of
calculated load for low-flow and storm-runoff conditions (fig. 7). Annual low-flow loads were calculated by multiplying mean low-flow
concentrations (table 4) by the mean annual low-flow
volumes (table 2) and by factors that account for the unit conversions of
liters to cubic feet, acre-feet to cubic feet, and milligrams or micrograms to pounds. Mean
storm-runoff loads were calculated in the same manner using mean storm-runoff concentrations
(table 5) and mean annual storm-runoff volumes
(table 2) and factors that account for appropriate unit conversions. Mean
annual constituent loads were calculated by adding mean annual low-flow loads to the mean
annual storm-runoff loads.

Figure 7 shows the estimated mean annual loads for
low flow and storm runoff for 10 constituents. Of the three sites, Corral Creek contributed
the most mass for 8 of the 10 constituents. Quarry Creek exceeded the mean annual loads in
Corral Creek for dissolved solids and dissolved phosphorus. The unnamed tributary contributed
the least mass of the three watersheds for all 10 constituents.

Storm runoff contributed more than one-half of the mean annual loads for most of the 10
constituents. More than 70 percent of the mean annual loads for suspended solids and total
recoverable copper, lead, and zinc were contributed by storm runoff. Low flow contributed more
than one-half the mean annual loads of dissolved solids at all three sampling sites, total
nitrogen at the unnamed tributary site, and dissolved phosphorus at the Quarry Creek and the
unnamed tributary sites.

Mean annual yields of the 10 selected constituents for each site were estimated by dividing
the loads (fig. 7) by the area of the
respective watershed. The watershed area, shown in table 1, was
converted from square miles to acres as part of the calculation. Mean annual constituent
yields were calculated by adding mean annual low-flow yields to the mean annual storm-runoff
yields.

The mean annual yield of chemical oxygen demand for Corral Creek was nearly twice the amount
of the yields from the other two watersheds (fig.
8). Yields during storm runoff contributed more than one-half of the mean annual yields of
chemical oxygen demand estimated for all three sampling sites, the most being for Corral Creek
where 80 percent of the annual chemical oxygen demand yield was from storm runoff.

Mean annual yields of dissolved solids were about 1,000 lb/acre from Quarry Creek, 700 lb/acre
from the unnamed tributary, and 500 lb/acre from Corral Creek. Low flow contributed more than
one-half of the mean annual yields of dissolved solids for all three watersheds. Low-flow
yields of dissolved solids for the Quarry Creek watershed were more than total yields
contributed from the other two watersheds.

The Corral Creek watershed yielded about four times the amount of suspended solids per acre as
the other two watersheds contributed. A possible explanation for this large yield is
construction activities within the Corral Creek watershed that took place during the study.
Vegetation was cleared at two different sites to construct new buildings, parking lots, and
access roads. When storms occurred, runoff from these construction sites probably transported
large amounts of suspended solids from the exposed soils into Corral Creek. The amount of
suspended solids contributed during low flow was insignificant at all sites when compared to
the amounts contributed during storm runoff.

The yields of nutrient constituents from the three watersheds varied among sites. The unnamed
tributary watershed had the largest yields of total nitrogen and dissolved phosphorus of the
three watersheds. Fertilizers used to maintain lawns and the golf course within this watershed
are possible sources for these large yields. Most of the mean annual yields of nutrient
constituents were contributed during storm runoff. The exceptions were total nitrogen from the
unnamed tributary watershed and dissolved phosphorus from the Quarry Creek and the unnamed
tributary watersheds, where low flow contributed larger yields than storm runoff.

Mean annual yields of total recoverable copper, lead, and zinc were largest from the Corral
Creek watershed. The unnamed tributary watershed had the smallest mean annual yield of total
recoverable copper and zinc, and the second highest mean annual yield of lead.

Generally, small variability of yields among the three watersheds indicates the differences in
land uses are small enough that distinction among watersheds is unclear. Large yields of
chemical oxygen demand, suspended solids, and total recoverable metals from the Corral Creek
watershed during storm runoff are probably related to the erosion of exposed soils from two
construction sites within the watershed. The small yields of suspended solids and total
recoverable copper and zinc from the unnamed tributary watershed are probably related to the
flow-retention characteristics of the lakes upstream from the sampling site. Discharges from
the lakes during a storm increase depending on the amount of inflow into the lakes. However,
increased discharge from the lakes is not necessarily storm runoff from that particular storm.
In fact, water entering the lakes could be impounded for days, weeks, or months depending on
the amount of subsequent inflow. Once storm runoff enters the lakes, velocities are greatly
reduced, and suspended solids settle out. Also, dissolved contaminants in the storm runoff may
be diluted by residual lake water. For these reasons, water discharging from the lakes during
storm runoff probably has smaller concentrations of dissolved constituents, suspended solids,
and total recoverable metals compared to inflowing storm-runoff concentrations.

Multiple regression models for estimating single-storm runoff loads and mean concentrations
developed by Driver and Tasker (1990) were used for 10 of the constituents addressed in this
study. These regression models were developed from data collected during EPA's Nationwide
Urban Runoff Program (NURP; U.S. Environmental Protection Agency, 1983) in the late 1970s and
early 1980s and include three groups delineated on the basis of mean annual rainfall. Region I
models were used in areas with mean annual rainfall between 0 and 20 in., Region II models
were used in areas with mean annual rainfall between 20 and 40 in., and Region III models were
used in areas with mean annual rainfall amounts greater than 40 in. Although the 30-year
(1961-90) mean annual rainfall at Leavenworth, Kansas, is 40.34 in. (NOAA, 1992), the models
for Region II were used for this study because the mean annual rainfall is only slightly
larger than 40 in. and Region II models were developed using data from nearby Kansas City,
Missouri. All the models were developed using ordinary least-squares regression. Ordinary
least-squares regression cannot be used with censored data. Nine of 21 cadmium concentrations
determined for this study were less than the analytical report level (censored data);
therefore, cadmium loads and concentrations were not modeled.

Storm-runoff loads, volumes, and mean concentrations were modeled using some or all of the
following climatic, physical, and land-use characteristics (Driver and Tasker, 1990):

Impervious area (IA), as a percentage of total contributing drainage-basin area.

Industrial land use (LUI), as a percentage of total contributing drainage-basin area.

Commercial land use (LUC), as a percentage of total contributing drainage-basin area.

Residential land use (LUR), as a percentage of total contributing drainage-basin area.

Nonurban land use (LUN), as a percentage of total contributing drainage-basin area.

Population density (PD), in people per square mile (6,200 in 1996; U.S. Army, Fort
Leavenworth, oral commun., 1997).

Table 3 of Driver and Tasker (1990) lists the three-variable load models. These models were
developed using TRN, DA, and IA. Table 1 of Driver and Tasker (1990) lists the multivariate
load models for estimating selected storm-runoff loads. These models were developed using all
12 of the climatic, physical, and land-use characteristics. Multivariate models for estimating
selected mean concentrations of storm runoff are listed in table 5 of Driver and Tasker
(1990). These models were developed considering all 12 of the climatic, physical, and land-use
characteristics.

Constituent loads during storm runoff are dependent on several physical parameters such as
storm characteristics, antecedent conditions, and land use. Storm-runoff loads were calculated
for each storm sample. Storm-runoff loads were calculated by multiplying the mean storm-runoff
concentration (table 8) by the total storm-runoff volume
(table 2) and by factors that account for the unit conversions of liters
to cubic feet and milligrams or micrograms to pounds. The total storm-runoff volume for each
storm was calculated using the streamflow hydrograph and rainfall data. One of the six
storm-runoff samples collected at Quarry Creek was affected by flow contributed by the levee
pump upstream from the site.

The maximum storm-runoff load for most of the selected constituents occurred most often at the
Corral Creek sampling site. Storm-runoff loads of dissolved solids and dissolved phosphorus
were largest at the Quarry Creek sampling site. The storms with the smallest loads for all 10
constituents occurred at the unnamed tributary sampling site. These observations are probably
a function of watershed size.

The regression models developed for Region II were not applicable to the unnamed tributary
sampling site because of the three lakes upstream from the site. The models were originally
developed for watersheds without lakes upstream from sampling sites; therefore, the regression
models were used to estimate loads and concentrations for only the Quarry Creek and Corral
Creek sampling sites.

Storm-runoff loads and concentrations for 10 of the 12 NPDES properties and constituents were
estimated for each storm sampled using Region II regression models presented in Driver and
Tasker (1990). Correlation analysis was performed to determine how well the regression-derived
loads and mean concentrations compared to the calculated loads and mean concentrations
determined during this study. Correlations with coefficients (r) of 0.70 or greater indicate
that the regression-model results can explain about 50 percent (r², coefficient of
variation) or more of the variability in the storm-runoff load or concentration data collected
during this study. The level of significance (p-value) was calculated for each correlation to
determine the probability that correlation between the calculated and estimated values is not
significant. A level of significance less than 0.05 indicates that the correlation between the
calculated and estimated values is significant. For the purpose of this report, a level of
significance equal to or greater than 0.05 indicates that the correlation between the actual
and estimated values is not significant. Therefore, for the constituents with correlation
coefficients equal to or greater than 0.70 and a level of significance less than 0.05, the
regional regression models presented in Tasker and Driver (1990) are considered adequate for
estimating storm-runoff loads and concentrations in the Quarry and Corral Creek watersheds.

Overall, the regional-regression load models estimated the calculated storm-runoff loads much
better than the regional-regression concentration models estimated the mean concentrations.
The correlation coefficients for the three-variable load models were the largest for all
constituents except dissolved solids. The correlation coefficients for the three-variable load
models ranged from 0.63 to 0.95 and levels of significance less than 0.05
(table 6). The multivariate load models had correlation
coefficients that ranged from 0.58 to 0.95 and levels of significance less than 0.05. Eight of
the 10 correlations for both types of load models had coefficients equal to or greater than
0.70 and are, therefore, acceptable for estimating storm-runoff loads. The correlation
coefficients for the multivariate concentration models ranged from -0.51 to 0.53, and the
levels of significance were equal to or greater than 0.05. One-half of the multivariate
concentration models had correlation coefficients less than zero. The negative correlation
indicates an inverse relation (negative slope) between the calculated and estimated
concentrations, or as the calculated data increase the estimated data decrease. A positive
correlation coefficient indicates both data sets are increasing. Because of inverse
relations, small correlation coefficients, and large p-values, the multivariate concentration
models were considered unsatisfactory for use at Fort Leavenworth.

1Equation from table 3 in Driver and Tasker (1990). 2Equation from table 1 in Driver and Tasker (1990). 3Equation from table 5 in Driver and Tasker (1990).

Most of the three-variable load model's correlation coefficients were slightly larger than the
multivariate load model's correlation coefficients and, therefore, slightly better at
estimating the storm-runoff loads for the storms that were sampled. Overall, the
three-variable load models are the simplest method for estimating storm-runoff loads for the
10 constituents. Of the 10 constituents, the three-variable load model with the largest
correlation coefficient was total recoverable zinc. Figure 9 shows the relation between calculated and
estimated total recoverable zinc storm-runoff loads for the Quarry Creek and Corral Creek
sampling sites for the storms sampled. The least-correlated, three-variable load model was for
dissolved solids loads. The relation between calculated and estimated storm-runoff loads for
dissolved solids at the Quarry Creek and Corral Creek sampling sites for the storms sampled is
shown in figure 10.

The three-variable models appear to be most suitable for estimating future storm-runoff loads.
The three variables (DA, IA, and TRN) used in the model are easily obtained. DA
(table 1) for each watershed will likely remain the same, IA
(table 1) can be updated as necessary, and TRN for each storm can be
measured or the data obtained from the National Weather Service.

Storm runoff from urban areas may have concentrations and loads of contaminants that may
degrade local water quality and downstream receiving water. The U.S. Geological Survey, in
cooperation with the U.S. Army Environmental Office at Fort Leavenworth, Kansas, began a
2.5-year study in 1994 to characterize the quantity and quality of water in three selected
streams during low-flow (12 samples) and storm-runoff (21 samples) conditions at three
sampling sites on Fort Leavenworth. This characterization was used to determine if previously
developed regional regression models could reasonably estimate loads and concentrations of
selected water-quality constituents for urban watersheds in the Fort Leavenworth area. The
purpose of this report is to present water-quality data collected during low flow and storm
runoff to assess current (1994-96) conditions and possible methods for anticipating future
water-quality effects from storm runoff and changes in land use.

Fort Leavenworth is located on the west bank of the Missouri River, about 10 mi upstream from
Kansas City, Kansas. The study area consists of three watersheds that drain most of the urban
area of the fort. The study area is about 4.0 mi² and includes about 38 percent of Fort
Leavenworth's total area, about one-half of the adjacent Leavenworth Federal Penitentiary, and
a small part of the city of Leavenworth. Land uses within the study area consist mostly of
nonurban and urban open area with smaller commercial and residential areas.

Three sampling sites were established in May 1994 to monitor the streamflow and the water
quality of Quarry Creek, an unnamed tributary to the Missouri River, and Corral Creek.
Streamflow was monitored continuously, and water-quality samples were collected during low
flow and storm runoff to determine mean annual constituent concentrations and loads.

Mean annual concentrations of selected water-quality constituents were calculated for each
sampling site from samples collected during low-flow and storm-runoff conditions. Mean
constituent concentrations for the most part were smallest during low flow with the exception
of major ions, dissolved solids, and some nutrients. The largest mean chemical oxygen demands
during low flow and in storm runoff were in water from Corral Creek. Storm-runoff samples
generally had a larger chemical oxygen demand than low-flow samples. Major ion and dissolved
solids concentrations generally were largest during low flow in water from all three sampling
sites and were usually largest in water from Quarry Creek. Suspended solids concentrations in
storm-runoff samples were typically an order of magnitude larger than concentrations in
low-flow samples. Corral Creek, by far, had the largest concentrations of suspended solids of
the three sites. Nutrient concentrations were most affected by storm runoff in the unnamed
tributary watershed. Storm-runoff concentrations of total nitrogen and dissolved phosphorus
were smaller than low-flow concentrations from the unnamed tributary watershed. Concentrations
of total recoverable metals were much larger in storm-runoff samples than in low-flow samples.
Of the three sampling sites, water from Corral Creek generally had the largest concentrations
of metals during low flow and storm runoff. Total organic carbon concentrations were larger in
storm-runoff samples than in low-flow samples. Water from Corral Creek had the largest total
organic carbon concentrations of the three sampling sites.

Two volatile organic compounds where detected in low-flow water samples. Total chloroform was
detected in water samples from all three sampling sites during March 1996; concentrations
ranged from 0.2 to 0.5 µg/L. Total tetrachloroethylene was detected at 0.3 µg/L in
the March 1996 sample from Quarry Creek. Three storm-runoff samples for analysis of volatile
organic compounds were collected during three storms. Concentrations of volatile organic
compounds in the samples were not above the analytical reporting levels.

Acid-base/neutral organic compounds were not detected in any of the low-flow or storm-runoff
samples. Eight pesticides were detected in low-flow samples. Atrazine, prometon, and simazine
were detected in low-flow samples from all three sampling sites. Fifteen pesticides were
detected in storm-runoff samples collected from all three sampling sites. In water from Quarry
Creek, p,p' DDD; DDE; p,p' DDE; p,p' DDT; malathion, and 2, 4-D were detected in more than
one-half of the samples collected. More than one-half of the samples collected from the
unnamed tributary had detections of DDE; p,p' DDT; malathion; and 2, 4-D. Chlordane,
chlorpyrifos, Diazinon, malathion, and 2, 4-D were detected in more than one-half the samples
collected from Corral Creek. A sample collected from Quarry Creek on August 22, 1996, was the
only sample without a detection of 2, 4-D. None of the pesticide concentrations exceeded the
Maximum Contaminant Level values established by U.S Environmental Protection Agency
drinking-water regulations.

Mean annual loads of selected constituents were calculated for each watershed. The Corral
Creek watershed contributed the largest amount of mass for 8 of the 10 selected constituents.
Only the Quarry Creek watershed exceeded the mean annual load of the Corral Creek watershed
for dissolved solids and dissolved phosphorus. The Quarry Creek and Corral Creek watersheds
contributed more than 1.5 times the mass that the unnamed tributary watershed contributed for
all 10 selected constituents. Overall, storm runoff contributed more than one-half of the mean
annual load for most of the 10 selected constituents. In fact, more than 70 percent of the
mean annual loads of suspended solids and total recoverable copper, lead, and zinc were
contributed by storm runoff. Low-flow loads of dissolved solids at all three sampling sites,
total nitrogen at the unnamed tributary site, and dissolved phosphorus at the Quarry Creek and
the unnamed tributary sites contributed more than one-half the mean annual load.

Mean annual yields (mass per unit area) of selected constituents from each watershed indicated
few differences between watersheds. The lack of variability of yields among the three
watersheds indicates that differences in land uses are small enough that few distinctions can
be made between watersheds. The Corral Creek watershed contributed the largest yields for 7 of
the 10 selected water-quality constituents. Large yields of chemical oxygen demand, suspended
solids, and total recoverable metals during storm runoff from the Corral Creek watershed are
probably related to the erosion of exposed soils at construction sites within the watershed.
The mean annual yield of dissolved solids was largest from the Quarry Creek watershed. The
largest mean annual yields of total nitrogen and dissolved phosphorus were from the unnamed
tributary watershed. Overall, storm runoff contributed more than one-half of the mean annual
yields for chemical oxygen demand, suspended solids, most of the selected nutrient
constituents, and all three of the selected total recoverable metals. In fact, more than 70
percent of the mean annual mean yields of suspended solids and total recoverable copper, lead,
and zinc were contributed by storm runoff. Low-flow yields of dissolved solids in water from
all three sampling sites, total nitrogen in water from the unnamed tributary, and dissolved
phosphorus in water from Quarry Creek and the unnamed tributary contributed more than one-half
the mean annual load. Low yields of suspended solids and total recoverable copper and zinc
from the unnamed tributary watershed are probably related to retention-storage effects from
lakes upstream from the sampling site.

Procedures for estimating single-storm runoff loads and mean concentrations developed by
Driver and Tasker (1990) for each of 10 constituents were used in this study. Storm-runoff
loads and mean concentrations were modeled using climatic, physical, and land-use
characteristics. Load models estimated the calculated storm-runoff loads much better than the
concentration models estimated the mean concentrations. The correlation coefficients for the
three-variable load models ranged from 0.63 to 0.95. Eight of the 10 models had correlation
factors greater than 0.70 and are considered, therefore, suitable for estimating storm-runoff
loads, whereas none of the values of the correlation coefficients for multivariate
concentration models were greater than 0.70.

Fishman, M.J., 1993, Methods of analysis by the U.S. Geological Survey National
Water-Quality Laboratory-methods for the determination of inorganic and organic
constituents in water and fluvial sediments: U.S. Geological Survey Open-File Report
93-125, 217 p.

Hammer, M.J., 1986, Water and wastewater technology: New York, John Wiley and
Sons, 550 p.